This application is directed to the promotion of effective antioxidant and antiwear activity in various lubricants and liquid hydrocarbon fuels. More particularly this invention is directed to compositions containing multifunctional antioxidant/antiwear additives comprising hindered phenolic phosphorodithioate-derived alcohol borates and to the additives themselves.
The use of hindered phenolic compounds, such as di-tertiary butyl paracresol, for their antioxidant properties in a variety of lubricant, polymer and elastomer applications is well known.
The use of phosphorodithioates have found widespread use for several decades in engine oils as multifuctional antiwear and bearing corrosion inhibiting additives, for example ZnDTP.
The use of borate esters has been widely reported as having beneficial multifunctional friction reducing properties. Borate esters of hindered phenols are disclosed in U.S. Pat. No.3,347,783 and U.S. Pat. No. 3,359,298. Re 32,295 (November, 1986) discloses the use of the reaction products of (1) a hindered phenol, (2) a boron compound and an amine as having friction reducing fuel saving properties.
It has now been found that the use of hindered phenolic/phosphorodithioate-derived alcohol borates provide exceptional antioxidant and antiwear activity and additionally with potential corrosion inhibiting, antifatigue and high temperature stabilizing properties.
Accordingly, it is an object of the present invention to provide novel additive products, suitable for use as antioxidant and antiwear multifunctional additives in various lubricant media and liquid hydrocarbon fuels.